共查询到19条相似文献，搜索用时 890 毫秒
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干旱区分根交替膜下滴灌对棉花生长和水分利用效率的影响 总被引：1，自引：0，他引：1
为探讨干旱区农业节水的途径,以棉花为供试作物,采用2种不同的灌水方式,研究了干旱区分根交替膜下滴灌对棉花生长和水分利用效率的影响。结果表明,在大田条件下,交替滴灌与常规滴灌的光合速率相比差异未达到显著水平,棉花株高在交替滴灌处理下均大于常规滴灌处理,而交替滴灌处理下蒸腾速率在整个生育期均低于常规滴灌处理。交替滴灌使棉花根系经受一定程度的水分胁迫锻炼,从而刺激根系的生长发育,因此交替滴灌对棉花根系生长有显著促进作用。相比常规滴灌,交替滴灌抑制了棉花蒸腾速率,即交替滴灌通过减少棵间蒸发和作物蒸腾耗水来提高了棉花的水分利用效率。同等产量水平下与常规滴灌相比,干旱区棉花交替滴灌可节省20.3%的灌水量,节水效果明显。 相似文献
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不同沟灌方式下夏玉米棵间蒸发试验 总被引：5，自引：0，他引：5
采用常规沟灌和交替隔沟灌技术,研究了不同水分处理(水分控制下限为田间持水率的80%、70%、60%)夏玉米的棵间蒸发。结果表明:常规沟灌的灌后蒸发和全生育期棵间蒸发量均大于交替隔沟灌,灌水后短期内由于表层土壤含水率较高,土壤蒸发较大;在满足作物蒸腾耗水的基础上,交替隔沟灌减小了灌溉湿润面积而减小无效蒸发耗水;不同沟灌方式下土壤蒸发与表层土壤含水率呈明显的脉冲波动变化,而深层土壤含水率波动较弱;表层土壤含水率和叶面积指数对棵间蒸发影响明显,二者与相对土面蒸发强度均有良好的指数函数关系。水分下限控制合适,交替隔沟灌棵间蒸发与蒸腾耗水明显降低,是夏玉米适宜的灌水方式。 相似文献
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立体种植农田不同生育期及土壤水分的根系分布特征 总被引：6，自引：0，他引：6
在立体种植农田中,作物根系分布是影响作物间水肥竞争及利用效率的首要因素。针对滴灌条件下番茄套种玉米立体种植农田设置高(T1)、中(T2)、低(T3)3个土壤水分处理,研究不同水分处理对立体种植农田不同位置土壤含水率、作物根系分布的影响,探讨立体种植农田根系在不同生育期生长发育特征。结果显示:立体种植农田番茄侧土壤含水率平均值显著低于玉米侧,膜内土壤含水率明显高于膜外土壤含水率,膜内不同位置土壤含水率无明显差异;随着生育期的推进作物间根系呈"不交叉—轻度交叉—完全交叉—轻度交叉"规律;随着土壤含水率的增加根系总量呈增长趋势,在0~30 cm的滴灌湿润区,作物根系分布最密集,约占总根系的60%~70%,且高水分处理根量显著大于低水分处理,根长密度、根表面积密度、根体积密度以及根重密度均呈现T1T2T3的趋势,而在非滴灌主要湿润区则正好相反;累积根系分布曲线分析显示随着土壤含水率增加根系向土壤下层生长,随着生育期推进根系向作物中间发展。立体种植农田作物在不同生育期根系分布变化明显,同时土壤水分对根系分布影响较大。 相似文献
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交替隔沟灌条件下夏玉米棵间蒸发研究 总被引：1，自引：0，他引：1
利用微型蒸发器观测了交替隔沟灌和常规沟灌条件下夏玉米的棵间蒸发量,分析了棵间蒸发、降雨量和参照腾发量的变化趋势以及不同土壤水分处理下隔沟灌和常规沟灌夏玉米棵间蒸发的日变化规律;探讨了相对蒸发强度与叶面积指数之间的关系,并拟合了棵间蒸发与叶面积指数之间的回归方程;最后指明了在充分供水条件下,相对蒸发强度与表层土壤含水量有极其敏感的关系.试验结果表明,交替隔沟灌条件下的棵间蒸发量小于相同水分处理的常规沟灌的棵间蒸发量,随着土壤水分下限值的增加,交替隔沟灌和常规沟灌间棵间蒸发量的差值越来越小;相对蒸发强度随着叶面积指数的增加而下降,随着表层土壤含水量的增加而增加. 相似文献
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根系分区交替滴灌条件下葡萄根系分布特征及生长动态 总被引：7，自引：0，他引：7
采用原位取土法和根系生态监测系统连续两年研究了葡萄的根系空间分布和全生育期根系生长动态,结果表明:葡萄根系在水平方向主要分布在距离树干100 cm的范围内,占到总根系的80％以上,而且在径向方向呈指数衰减;葡萄根系在垂直方向主要分布在0～60 cm范围的土层内,占到总根系的75％以上.根系分区交替滴灌条件下干燥区与湿润区根系生长是不同的,葡萄的新生根系受到土壤水分条件的限制和自身生长的影响.在整个生育期,葡萄根系分区交替滴灌两侧根系生长均呈抛物线变化. 相似文献
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植物护坡效果与根系在土壤中的空间造型和分布(即根系构型)密切相关,研究不同土壤初始含水率和滴头流量对红黏土内水分运移的影响规律,对合理匹配土壤湿润体与植物根系分布情况,准确调控植物根系构型,提高植物边坡固土能力具有重要意义。采用室内试验的方法,在间接地下滴灌的条件下,观测土壤初始含水率和滴头流量对土壤湿润体特征值、湿润锋运移速度和含水率分布情况的影响。试验研究发现湿润锋运移的形状近似椭圆形,而湿润体的形状则近似为椭球体。随着土壤初始含水率的增加,湿润体水平方向对称轴不断下移,水分趋于垂直向下运移,随时间呈对数函数变化。在相同的滴灌量条件下,流量较小的湿润体的范围稍大于流量较大的湿润体范围,但湿润锋的半径均随时间呈幂函数变化。滴灌初期,同一时刻湿润锋运移速度随滴头流量的增大而增大,但随滴灌时间的延长,这一现象逐渐减弱。滴头流量大时,水分向水平方向运移的趋势明显,而滴头流量小时,水分向垂直方向运移的趋势更优。不同滴头流量和土壤初始含水率会形成不同形状和大小的湿润体,也会导致湿润体含水量分布不同。在调控所需的植物根系构型时,可通过控制滴头流量和土壤初始含水率来控制植物根系分布情况,提高植物根系固土的能力。 相似文献
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小麦/玉米套作及其相应单作群体棵间土壤蒸发规律 总被引：1，自引：1，他引：0
通过大田实验,对比分析河套灌区小麦/玉米套作与单作小麦、单作玉米棵间土壤蒸发的差异及其规律。结果表明,单作小麦、小麦/玉米套作和单作玉米的棵间土壤蒸发量占总耗水量的比例分别为28.8%、38.6%和29.9%;套作群体全生育期的棵间土壤蒸发量显著高于单作,且日均棵间土壤蒸发量为1.06 mm/d,高于单作小麦0.85 mm/d和单作玉米0.90 mm/d。不同生育期棵间土壤蒸发的日变化规律基本一致,峰值出现在中午12:00~14:00之间,不同种植模式下棵间蒸发占蒸散发的比例与叶面积指数均呈良好的指数关系,同时棵间土壤蒸发与表层土壤含水率均呈脉冲波动变化,且灌溉后波动幅度增大。 相似文献
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Water use efficiency and fruit quality of table grape under alternate partial root-zone drip irrigation 总被引：3，自引：0，他引：3
Taisheng Du Shaozhong Kang Jianhua Zhang Fusheng Li Boyuan Yan 《Agricultural Water Management》2008,95(6):659-668
Two-year field experiments were conducted to investigate the effect of alternate partial root-zone drip irrigation on fruit yield, fruit quality and water use efficiency of table grape (Vitis vinifera L. cv Rizamat) in the arid region of northwest China. Three irrigation treatments were included, i.e. CDI (conventional drip irrigation, both sides of the root-zone irrigated), ADI (alternate drip irrigation, both sides of the root-zone irrigated alternatively with half the water) and FDI (fixed drip irrigation, only one side of the root system irrigated with half the water). Results indicated that compared to CDI, ADI kept the same photosynthetic rate (Pn) but reduced transpiration rate, thus increased leaf water use efficiency (WUE) of table grape. And diurnal variation of leaf water potential showed no significant differences during 7.00 a.m. to 14.00 p.m. in both years. ADI also produced similar yield and improved WUEET by 26.7–46.4% and increased the percentage of edible grape by 3.88–5.78%, vitamin C content in the fruit by 15.3–42.2% and ratio of total soluble solid concentration/titrated acid in both years as compared to CDI. Thus ADI saved irrigation water, improved the water use efficiency and fruit quality of table grape without detrimental effect on the fruit yield in arid region. 相似文献
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开沟覆膜滴灌条件下土壤水、温变化规律研究 总被引：1，自引：0，他引：1
新疆是中国葡萄重要的生产基地,但每年因盐碱与缺水导致减产现象严重。开沟覆膜滴灌技术结合膜下滴灌与开沟技术优点,理论上可有效改善作物生长的水土环境。为研究桁架葡萄下开沟覆膜滴灌技术对土壤水分与温度变化的影响,在石河子147团6连试验地用EM50仪器开展土壤水分、温度监测试验。研究结果表明:①在开沟模式为20 cm×100 cm,灌水定额为300 m3/hm~2时,无论是膜中还是膜边,灌水前后土壤含水量维持在0.22~0.38,满足作物根系吸水。加大灌水定额,在覆膜影响下,滴灌带表面积水区面积增大,使得在滴头下方形成饱和区增大;随着开沟深度的增大,覆膜中土壤含水量变化不明显,覆膜边呈下降趋势。②温度监测表明,无论是温度上升期(12时),还是夜间下降期(24时),土体温度变化幅度均在15~31℃,给葡萄生长提供良好的温度环境,利于葡萄产量与品质的提高。 相似文献
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A mathematical model for simulating water balances in cropped sandy soil with conventional flood irrigation applied 总被引：1，自引：0，他引：1
Xi-Bin Ji Er-Si Kang Ren-Sheng Chen Wen-Zhi Zhao Zhi-Hui Zhang Bo-Wen Jin 《Agricultural Water Management》2007
In this paper, a model that integrates various complex model components for the purposes of water balance modeling throughout crop development in arid inland region under the conventional flood irrigation practiced is presented. These components are modules for calculating dynamic soil water content based Richard's equation, potential and actual evapotranspiration, and crop root water uptake. Soil water content in the active root zone and soil evaporation simulation obtained from the model were test using field data in 2003. The low values of MARE and high values of R2 and PE in the active root zone of soil profile as well as daily soil evaporation indicated that the soil water balance simulation model presented in the paper can be used with reliable accuracy to simulate the components of water balance in cropped sandy soil under the conventional flood irrigation condition in arid inland regions. The model simulation on components of water balance using observed field data in 2004 indicated that large quantities – about 43% of irrigation water (amounting to 840 mm) – were consumed by deep percolation, only small (less than 41%) proportions of irrigation water used by the plants for transpiration. The current irrigation scheme is characterized by the unreasonable agricultural water management with the waste of water in the irrigational system in this region. The impact of irrigation scheduling on water balance presented in this paper showed that the reasonable irrigation scheme with more frequent irrigation and less amounts is more suitable for the irrigation of spring wheat in Heihe River basin, northwest China. Therefore, to establish a decision-making system for agricultural irrigation scheme and to utilize the limited water resources in this region have become an urgent problem that needs to be solved. 相似文献
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针对贺兰山东麓砂质酿酒葡萄园漏水漏肥,水分利用率低等问题,采用田间试验,分别设置沟灌、单管滴灌和双管滴灌的方式,研究土壤水分分布及葡萄需水规律,从而制定适宜的灌溉制度。结果表明,沟灌水分下渗基本在70cm内的根系分布层,灌溉后期含水率低,灌溉周期为13d;双管滴灌水平侧渗区域主要集中在20～45cm的葡萄毛根活动区域,垂直入渗在在60cm根系分布区内,灌溉周期为9d;单管滴灌垂直下渗速率高于侧渗速率,灌溉周期为7d。单管滴灌方式便于大规模的葡萄机械化管理,最佳水分管理方式为增加单次灌溉时间让单次灌水量达到450m3/hm2。 相似文献
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直插式根灌技术的研究与应用 总被引：1，自引：0，他引：1
直插式根灌技术,是一种新型的节水灌溉技术,它结合了地面滴灌与地下渗灌的优点,能够把水直接灌溉到一定深度土壤层,起到对植物根系层,进行直接灌溉的目的;能有效减少表层土壤水分蒸发损失,提高灌水效率、提高灌溉水的有效利用率。过去的地埋式渗灌技术,有较好的灌水效果和抑制表层土壤水分蒸发损失作用,但其易堵塞、检修难的缺点,限制了地下渗灌技术的发展。地表滴灌技术成熟,但其表层土壤水分蒸发损失,影响滴灌水分的利用效率和灌水效率。为了结合滴灌与渗灌的优势,克服滴灌与渗灌的缺点;所以,开展对直插式根灌技术的研究,把地表滴灌的水分,直接引灌到一定深度的土壤层,实现土壤的越层灌溉,起到较好的灌水效果,根灌产品,安装简便,便于维护。 相似文献
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《Agricultural Water Management》2001,52(1):53-71
The influences of water quantity and quality on young lemon trees (Eureka) were studied at the University of Jordan Research Station at the Jordan Valley for 5 years (1996–2000). Five water levels and three water qualities were imposed via trickle irrigation system on clay loam soil. The primary effect of excess salinity is that it renders less water available to plants although some is still present in the root zone. Lemon trees water requirements should be modified year by year since planting according to the percentage shaded area, and this will lead into substantial water saving. Both evaporation from class A pan and the percentage shaded area can be used to give a satisfactory estimate of the lemon trees water requirement at the different growth stages. The highest lemon fruit yield was at irrigation water depth equal to evaporation depth from class A pan when corrected for tree canopy percentage area. Increasing irrigation water salinity 3.7 times increased average crop root zone salinity by about 3.8–4.1 times.The high salt concentration at the soil surface is due to high evaporation rate from wetted areas and the nature of soil water distribution associated with drip irrigation system. Then, the salt concentration decreased until the second depth, thereafter, salt concentration followed the bulb shape of the wetted soil volume under trickle irrigation. Irrigation water salinity is very important factor that should be managed with limited (deficit) irrigation. But increasing amount of applied saline water could result in a negative effect on crop yield and environment such as increasing average crop root zone salinity, nutrient leaching, water logging, increasing the drainage water load of salinity which might pollute ground water and other water sources. 相似文献